BEGIN;
BEGIN
EXPLAIN (ANALYZE, BUFFERS)
select
	100.00 * sum(case
		when p_type like 'PROMO%'
			then l_extendedprice * (1 - l_discount)
		else 0
	end) / sum(l_extendedprice * (1 - l_discount)) as promo_revenue
from
	lineitem,
	part
where
	l_partkey = p_partkey
	and l_shipdate >= date '1997-12-01'
	and l_shipdate < cast(date '1997-12-01' + interval '1 month' as date);
                                                                               QUERY PLAN                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Aggregate  (cost=1173300.46..1173300.47 rows=1 width=29) (actual time=7097.897..7097.897 rows=1 loops=1)
   Buffers: shared hit=226425 read=232411 written=40
   ->  Hash Join  (cost=101771.43..1159818.00 rows=770426 width=29) (actual time=1965.270..6706.814 rows=772864 loops=1)
         Hash Cond: (lineitem.l_partkey = part.p_partkey)
         Buffers: shared hit=226425 read=232411 written=40
         ->  Bitmap Heap Scan on lineitem  (cost=16249.43..1062739.61 rows=770426 width=12) (actual time=614.378..4604.869 rows=772864 loops=1)
               Recheck Cond: ((l_shipdate >= '1997-12-01'::date) AND (l_shipdate < '1998-01-01'::date))
               Heap Blocks: exact=416198
               Buffers: shared hit=185908 read=232403 written=40
               ->  Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx  (cost=0.00..16056.83 rows=770426 width=0) (actual time=412.095..412.095 rows=781171 loops=1)
                     Index Cond: ((l_shipdate >= '1997-12-01'::date) AND (l_shipdate < '1998-01-01'::date))
                     Buffers: shared read=2113
         ->  Hash  (cost=60522.00..60522.00 rows=2000000 width=25) (actual time=1339.677..1339.677 rows=2000000 loops=1)
               Buckets: 2097152  Batches: 1  Memory Usage: 131903kB
               Buffers: shared hit=40514 read=8
               ->  Seq Scan on part  (cost=0.00..60522.00 rows=2000000 width=25) (actual time=0.016..657.369 rows=2000000 loops=1)
                     Buffers: shared hit=40514 read=8
 Planning time: 3.003 ms
 Execution time: 7101.818 ms
(19 rows)

COMMIT;
COMMIT